Grain bin aeration duct

ABSTRACT

An aeration duct apparatus for a grain bin has an air chamber with louvered side walls, which comprise a plurality of wall slats that extend the length of the chamber and slope from inner side edges thereof downward and outward to outer side edges thereof, and are spaced apart to form air gaps between adjacent slats. The slats prevent grain from flowing through the air gaps into the air chamber. In one embodiment the outer side edge of each slat is closer to a center of the air chamber than the outer side edge of an adjacent slat below, and farther from the center than the outer side edge of an adjacent slat above, such that the right and left louvered side walls each slope inward toward the center of the air chamber from lower edges thereof to upper edges thereof. The duct is well suited to hopper bottom bins.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Canadian Patent Application No. 2,707,941, filed Jun. 15, 2010, the disclosure of which is incorporated by reference in its entirety.

DESCRIPTION OF THE INVENTION

1. Field of the Invention

This invention is in the field of grain storage and aeration bins and in particular an aeration duct that is well suited for hopper bottom grain bins.

2. Background

Aeration systems for grain bins include a perforated duct located inside the bottom of a grain bin, and a fan directing air into the duct, out through the perforations and up through the grain and out through a vent in the roof of the bin. The fan is sized to provide the desired airflow for the height and volume of grain in the bin, and the duct area must be large enough to provide sufficient perforations so that the desired volume of air can flow through the perforations without developing excessive back-pressure. Such an aeration system is disclosed for example in U.S. Pat. No. 4,688,332 to Kallestad, et al.

In flat bottom bins the duct can be provided by a fully or partially perforated floor with the fan directing the airstream under the floor, or by a horizontal tube or the like with perforated walls or network of tubes resting on the bin floor and the fan directing the airstream into the tubes. The large perforated area of a fully or partially perforated floor generally provides a satisfactory air flow. Where tubes are used, a network in a “Y” or “X” configuration will usually provide sufficient perforated tube wall area for the required air flow.

The fully perforated is also beneficial as it is desirable to have the air stream evenly distributed through the bottom of the grain bin, so the air flows upward through the grain evenly across the bin. Tube and like systems are generally less costly, and can be easily placed after the bin is constructed, and air flow is generally satisfactory across the bin for the purpose.

Hopper bottom bins have become popular since they are easily cleaned out. These bins have a cone shaped floor with walls sloping to a central discharge chute so that all the grain flows down the walls to the chute, and no manual removal is required as in a flat floor bin. Since the floor of a hopper bottom bin slopes it the length of a horizontal tube network in the hopper is limited. To provide added wall area, vertical tubes with concentric perforated inner and outer walls are commonly used, such as the Rocket™ vertical aeration systems sold by Edwards Grain Guard of Lethbridge, Alberta, Canada. These tubes extend upward in the center of the bin, and air flows out the perforated sides and out the open bottom and upward through the grain in the bin.

U.S. Pat. No. 7,568,297 to Pierson et al. discloses an aeration duct for a hopper bottom bin that has a pyramid frame in the center of the bin with legs attachable to the sloped floor of the hopper bottom, and concave perforated walls attached to the legs. An air stream is directed into the interior of the frame, and moves out into the grain through the perforated walls.

Assie Industries of St. Brieux Saskatchewan Canada makes an aeration duct for hopper bottom bins that comprises an enclosed box with an open bottom that extends across the cone at the bottom of the bin. Air is directed into the enclosure and then out the open bottom along the length of the box and up through the grain.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an aeration duct, particularly suited for hopper bottom bins, that overcomes problems in the prior art.

In a first embodiment the present invention provides an aeration duct apparatus for a grain bin. The apparatus comprises an air chamber with right and left louvered side walls, end walls at opposite ends of the right and left louvered walls, a closed top above the right and left louvered side walls, and an open bottom. The right and left louvered side walls each comprise a plurality of wall slats extending substantially from one end wall to the opposite end wall and sloping from inner side edges thereof downward and outward to outer side edges thereof, and spaced apart such that air gaps are formed between adjacent slats. The slats are configured such that grain on an exterior of the air chamber is prevented from flowing through the air gaps to an interior of the air chamber.

In a second embodiment the present invention provides a hopper bottom bin and aeration apparatus comprising a cone shaped floor with bin walls extending upward from a perimeter of the cone shaped floor, and cone walls sloping downward from the perimeter to a port at a bottom of the cone shaped floor. An air chamber extends across the cone shaped floor between the perimeter and the port, the air chamber comprising right and left louvered side walls, end walls at opposite ends of the right and left louvered walls adjacent to the cone walls, a closed top above the right and left louvered side walls, and an open bottom. The right and left louvered side walls each comprise a plurality of wall slats extending substantially from one end wall to the opposite end wall and sloping from inner side edges thereof downward and outward to outer side edges thereof, and spaced apart such that air gaps are formed between adjacent slats. The slats are configured such that grain on an exterior of the air chamber is prevented from flowing through the air gaps to an interior of the air chamber.

The invention provides an aeration duct apparatus with reduced restriction to air flow and even air distribution across a substantial portion of the width of a bin. The non-restrictive airflow capabilities of the invention make it particularly suited to use in hopper bottom bins.

DESCRIPTION OF THE DRAWINGS

While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:

FIG. 1 is a perspective view of an embodiment of an aeration duct apparatus of the present invention for use in a grain bin;

FIG. 2 is a schematic view of the embodiment of FIG. 1 installed in a hopper bottom bin;

FIG. 3 is a schematic sectional view of the sloped louvered side walls of the air chamber of the embodiment of FIG. 1;

FIG. 4 is a schematic top view looking down on the embodiment of FIG. 1 installed in the hopper bottom bin as in FIG. 2;

FIG. 5 is a schematic exploded view showing a convenient construction of the air chamber of the embodiment of FIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1 is a schematic view of an embodiment of an aeration duct apparatus 1 of the present invention for a grain bin. While it is contemplated that the apparatus 1 could be used in a flat bottom grain bin its high air flow capabilities make it particularly suited to reducing restriction to air flow in the more confined quarters of a hopper bottom bin. A typical hopper bottom bin 3 is schematically illustrated in FIG. 2 with the aeration duct apparatus 1 installed. The hopper bottom bin 3 has a cone shaped floor 5 with bin walls 7 extending upward from a perimeter 9 of the floor 5 and cone walls 11 sloping downward from the perimeter 9 to a port 13 at a bottom of the cone shaped floor 5 where grain is drawn out of the bin 3.

The apparatus 1 comprises an air chamber 15 extending across the cone shaped floor 5 between the perimeter 9 and the port 13. An air conduit 17 has an output end 19 in the interior of the air chamber 15, and an input end 21 connected to an opening in the cone wall 11. In use a fan 23 is connected to input end 21 and directs an air stream through the air conduit 17 into the interior of the air chamber 15.

The air chamber 15 comprises right and left louvered side walls 25, end walls 27 at opposite ends of the right and left louvered walls 25 adjacent to the cone walls 11, a closed top 29 above the right and left louvered side walls 25, and an open bottom 31. In the illustrated air chamber 15, substantially vertical right and left lower side walls 26 extend downward from corresponding right and left louvered side walls 25 and serve to contain the air stream received through the conduit 17 and distribute same along the length of the air chamber 15.

The louvered side walls 25 comprise a plurality of wall slats 33 extending substantially from one end wall 27 to the opposite end wall 27 and sloping from inner side edges 33A thereof downward and outward to outer side edges 33B thereof, as schematically illustrated in FIG. 3. The slats 33 are spaced apart such that air gaps 35 are formed between adjacent slats 33 and configured such that grain 37 on an exterior 39 of the air chamber 15 is prevented from flowing through the air gaps 35 to an interior 41 of the air chamber 15. The slats 33 are configured such that the outer side edge 33B of a higher slat 33′ is vertically located below the inner side edge 33A of an adjacent slat 33″ below the higher slat 33′. Since grain does not flow uphill, the grain 37 cannot flow through the air gaps 35 into the interior 41 of the air chamber 15, but air can flow readily out into the grain. Air also moves out of the air chamber 15 through the open bottom 31 thereof.

While it is contemplated that the louvered side walls 25 could be substantially vertical, the illustrated air chamber 15 is configured to more evenly distribute the air coming out of the air gaps across the width of the air chamber 15 and so more evenly distribute the air to the grain above the air chamber 15. The outer side edge 33B of each slat 33 is closer to a center C of the air chamber 15 than the outer side edge of an adjacent slat 33 below each slat, and farther from the center C of the air chamber 15 than the outer side edge 33B of an adjacent slat 33 above each slat, such that the right and left louvered side walls 25 each slope inward toward the center C of the air chamber 15 from lower edges 43 thereof to upper edges 45 thereof.

A top view looking down at the apparatus 1 installed in a hopper bottom bin 3 is schematically illustrated in FIG. 4. The sloped louvered side walls 25 of the air chamber 15 provide a plurality of air gaps along the length and across the width of the air chamber 15. The air gaps 35 are relatively large compared to the total open area of the perforations in commonly used perforated ducts that are sometimes placed in about the same orientation as the illustrated air chamber 15. Restriction to air flow is significantly reduced and high air flows are possible. The airflow, indicated by the arrows 47, is distributed across a significant width of the bin 3 as is generally desirable.

A convenient construction for the air chamber 15 is illustrated in the schematic exploded end view of FIG. 5. The end walls 27 define slots 51 that correspond to a cross section of the slats 33, and the ends of the slats 33 extend into the slots 51 and are fastened to the end walls 25 by welding or the like. The end walls 27 are illustrated as solid with no perforations but it is contemplated that perforations could be provided if desired.

Looking at the cross section of the slat 33, the middle portion 53 of each slat 33 is substantially flat and parallel to adjacent slats 33 above and below each slat 33, providing a smooth air gap. Outer portions 55 of each slat 33 bend downward to a substantially vertical orientation following the vertical edge 57 of the end wall 27, and inner portions 59 of each slat bend upward and hook into the slot 51 so it does not slide down and out of the slot 51 during assembly. The downward and upward bends also move the outer side edge 33B of each slat down below the inner side edge 33A of the slat below so grain is prevented from flowing through the air gap 15 into the interior of the air chamber.

The closed top 29 of the air chamber comprises a roof panel 61 with right and left sides 61R, 61L sloping downward from a longitudinal axis LA thereof substantially parallel to mid-portions 53 of right and left top slats 33T of the right and left louvered walls 25 such that air gaps are formed between the right and left top slats 33T and the right and left sides 61R, 61L of the roof plate 61. The vertical right and left lower side walls 26 are provided by a panel 63 that has a top portion 65 configured the same as the slats 33, and a lower portion 67 that extends downward from corresponding right and left louvered side walls 25 along the outer edge 69 of the end wall 27. Thus an air gap is provided between the top portion of the panel 63 and the slat just above it.

Since the air chamber 15 is quite long, typically about 12 feet long, middle support are provided to support the relatively thin slats 33 and roof panel 61. The supports comprise a substantially vertical support plate 71 attached at lower right and left edges 71R, 71L thereof to the right and left lower side walls 26, typically by welding, and having an upper portion 73 configured to bear against bottom sides of the slats 33 and against the top of the air enclosure, roof panel 61. The support plate 71 defines a large air passage 75 in a central portion thereof to allow air to flow freely through the assembled air chamber. The support plate is inserted as indicated by the arrow up into the open bottom of the air chamber once the slats 33 and roof panel 61 are assembled, and then the upper portion 73 of the support plate 71 is attached to the slats 33 and roof panel 61 by welding or the like.

In the illustrated apparatus 1, the parts are conveniently joined together by welding however it is contemplated that a bolted together configuration could be used so that the apparatus could be collapsed into a more convenient form for shipping from a factory, and then assembled at the use location.

The invention thus provides an aeration duct apparatus for a hopper bottom bin with reduced restriction to air flow and even air distribution across a substantial portion of the width of the bin.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention. 

1. An aeration duct apparatus for a grain bin, the apparatus comprising: an air chamber with right and left louvered side walls, end walls at opposite ends of the right and left louvered walls, a closed top above the right and left louvered side walls, and an open bottom; wherein the right and left louvered side walls each comprise a plurality of wall slats extending substantially from one end wall to the opposite end wall and sloping from inner side edges thereof downward and outward to outer side edges thereof, and spaced apart such that air gaps are formed between adjacent slats but grain on an exterior of the air chamber is prevented from flowing through the air gaps to an interior of the air chamber.
 2. The apparatus of claim 1 wherein the outer side edge of each slat is closer to a center of the air chamber than the outer side edge of an adjacent slat below each slat, and farther from the center of the air chamber than the outer side edge of an adjacent slat above each slat, such that the right and left louvered side walls each slope inward toward the center of the air chamber from lower edges thereof to upper edges thereof.
 3. The apparatus of claim 2 wherein the slats are configured such that the outer side edge of a higher slat is vertically located below the inner side edge of an adjacent slat below the higher slat.
 4. The apparatus of claim 3 wherein a middle portion of each slat is substantially flat and parallel to adjacent slats above and below each slat.
 5. The apparatus of claim 4 wherein outer portions of each slat bend downward, and wherein inner portions of each slat bend upward.
 6. The apparatus of claim 5 wherein the outer portions of each slat are oriented substantially vertically.
 7. The apparatus of claim 1 wherein the closed top of the air chamber comprises a roof panel with right and left sides sloping downward from a longitudinal axis thereof substantially parallel to mid-portions of right and left top slats of the right and left louvered walls such that air gaps are formed between the right and left top slats and the right and left sides of the roof plate.
 8. The apparatus of claim 1 comprising substantially vertical right and left lower side walls extending downward from corresponding right and left louvered side walls, and a middle support comprising a substantially vertical support plate attached at lower right and left edges thereof to the right and left lower side walls and having an upper portion configured to bear against bottom sides of the slats and against the top of the air enclosure, and defining an air passage in a central portion thereof.
 9. The apparatus of claim 1 further comprising an air conduit having an output end in the interior of the air chamber, and an input end adapted to be connected to an opening in a wall of a grain bin.
 10. The apparatus of claim 1 wherein the end walls define slots that correspond to a cross section of the slats, and where ends of the slats extend into the slots and are fastened to the end walls.
 11. A hopper bottom bin and aeration apparatus comprising: a cone shaped floor with bin walls extending upward from a perimeter of the cone shaped floor, and cone walls sloping downward from the perimeter to a port at a bottom of the cone shaped floor; an air chamber extending across the cone shaped floor between the perimeter and the port; the air chamber comprising right and left louvered side walls, end walls at opposite ends of the right and left louvered walls adjacent to the cone walls, a closed top above the right and left louvered side walls, and an open bottom; wherein the right and left louvered side walls each comprise a plurality of wall slats extending substantially from one end wall to the opposite end wall and sloping from inner side edges thereof downward and outward to outer side edges thereof, and spaced apart such that air gaps are formed between adjacent slats; wherein the slats are configured such that grain on an exterior of the air chamber is prevented from flowing through the air gaps to an interior of the air chamber.
 12. The apparatus of claim 11 wherein the outer side edge of each slat is closer to a center of the air chamber than the outer side edge of an adjacent slat below each slat, and farther from the center of the air chamber than the outer side edge of an adjacent slat above each slat, such that the right and left louvered side walls each slope inward toward the center of the air chamber from lower edges thereof to upper edges thereof.
 13. The apparatus of claim 12 wherein the slats are configured such that the outer side edge of a higher slat is vertically located below the inner side edge of an adjacent slat below the higher slat.
 14. The apparatus of claim 13 wherein a middle portion of each slat is substantially flat and parallel to adjacent slats above and below each slat.
 15. The apparatus of claim 14 wherein outer portions of each slat bend downward, and wherein inner portions of each slat bend upward.
 16. The apparatus of claim 15 wherein the outer portions of each slat are oriented substantially vertically.
 17. The apparatus of claim 11 wherein the closed top of the air chamber comprises a roof panel with right and left sides sloping downward from a longitudinal axis thereof substantially parallel to mid-portions of right and left top slats of the right and left louvered walls such that air gaps are formed between the right and left top slats and the right and left sides of the roof plate.
 18. The apparatus of claim 11 comprising substantially vertical right and left lower side walls extending downward from corresponding right and left louvered side walls, and a middle support comprising a substantially vertical support plate attached at lower right and left edges thereof to the right and left lower side walls and having an upper portion configured to bear against bottom sides of the slats and against the top of the air enclosure, and defining an air passage in a central portion thereof.
 19. The apparatus of claim 18 wherein the upper portion of the support plate is attached to the slats.
 20. The apparatus of claim 11 further comprising an air conduit having an output end in the interior of the air chamber, and an input end connected to an opening in a cone wall.
 21. The apparatus of claim 11 wherein the end walls define slots that correspond to a cross section of the slats, and where ends of the slats extend into the slots and are fastened to the end walls. 